Figure 6

Model illustrating the possible role of RNP1 motif in the initiation of T-B cell spreading pathway (adapted from [13]). Epitopes containing the RNP1 motif (in dark blue) are presented to specific T cells that in turn activate B cells to produce anti-RNP1 antibodies (Abs). These B cells then bind and process the RNP1 epitope present within RNP1+ proteins, such as U1-70K (in blue) and U1-A (in green), but also the whole spliceosomal particle that contains RNP1-proteins, such as U1-C (in yellow) and SmD1 (in pink) proteins. This leads to the activation of Th and B cells and results in the production of diverse sets of auto-antibodies, which then deposit in tissues (IC, immune complexes) and trigger organ damage.